Pin retaining means



Fell 26, 1952 G. K. NEWELL PIN RETINING MEANS Filed NOV. 28, 1947 INVENTOR. @601299K Newell BY l QL@ 65M.

ATTORAEY Patented Feb. 26, 1952 PEN RETAINING MEANS George K. NewelLnear Pitcairn, Pa., assignor, to

Westinghouse Air Brake Company, a corporation of Pennsylvania Application November 28, 1947, Serial No. 788,627

3 Claims. 1

This invention relates to locking devices and more particularly to an improved locking pin and retaining means therefor.

In the copending application of 'Joseph C. McCune, Serial No. 637,302, filed DecemberV 27, 1945, now Patent No. 2,553,828, dated May 22, 1951, and assigned to the assignee of the present application, there is disclosed a rotatable friction eiement for use in vdisk brakes or the like.

The friction element therein disclosed comprises a plurality of removable brake shoe segments spaced apart about the periphery-of an annular body'member, and securing structure for securing adjacent ends of these shoe segments to each other and to said body member.

The above-mentioned securing structure in turn comprises torque transmitting members whichare spaced circumferentially about and rigidly secured to' and between two spaced apart flat annular rings which form the body member.

Each torque transmitting member comprises an inwardly projecting lug adapted to be connected to a rotatable brake member for rotation therewith, and two spaced apart outwardly projecting lugs adapted to t into accommodating openings in the respective ends of two adjacent brake shoe segments. A securing bar extends between these respective ends for holding the shoe segments in place on the outwardly projecting lugs. A U-shaped metal'strap fits over the securing bar for holding same in place. The metal strap includes two spacedapart arms which t into grooves formed in opposite sides of the torque transmitting member within the spacedapart flat annular rings which formthe body member. 7

A locking pin is t into registering openings eX- tending through the two arms of the metal strap, the torque transmitting member, and the annular rings of the body member, to secure said strap to said body member and thus hold 'the securingbar and thereby the adjacent ends of the brake shoe segments in place during rotation of the entire assembly. The pin is held in place by a wire or the like which is threaded into transverse openings in opposite ends thereof disposed within each of the opposite respective grooves in the torque transmitting member inside each adjacent at annular plate of the body member.

It is essential from the standpoint of safety to the .brake equipment and to operation of vehicles employing said equipment that the removable brake shoek segments comprised in this rotatable friction element positively remain in place duringsaid'operation. Since in the above'arrangement the locking pin is responsiblefor hold- 2 ing the shoe segments to the'body member, it naturallyffollows that it is highly desirable to provide reliable vmeans for retaining said locking pin in place.

It is thereforel one object of the invention to provide improved retaining means for an improved locking pin particularly` adapted for use in the above described rotatable friction element of a disk brake or' the like.

Itis another object of. the invention to provide anA improved lockingA pinandretaining means therefor which vmaybe readily assembled and disassembled by use ofthecommonest tools.

It isA still a further: object of the invention to provide an improved locking pin and retaining means therefor which will be reliable.

Other objects and advantagesr of the invention will hereinafter become obvious from the following detailed description thereof.

In theY accompanying drawing, Fig. 1 is an isometric-view of aportion of a disc brake element including 'the improved locking pin and a retainingelement therefor; Fig. 2 is a plan view of the development4 of .the pin retaining element shown in Fig. 1; Fig. 3 is anelevational view in the pinretaining'ielement shown in the former figure.

In the drawing, reference. numerals I and 2 designate two 'spacedrapartf members secured in common tov opposite sides of a member 3 in any suitable fashion'such'as by means of welds 4. The member3is provided with two oppositely disposedgrooves and 6 which open downwardly, asv viewed in the drawing'exposed to the inner faces `of members land 2 respectively-- Two spaced apart elements 1 and 8, each of substantially the same width as the width of the grooves 5 andf Ii'and of less thickness than the depth thereof; are :disposed in grooves 5 and 6, respectively. A clearancespace 9 'is formed between the outer-face of each element 1, 8 and the inner face of the respective members I, 2.

'According toa feature of the invention, the elements 1-and`8 arel removably secured in the respective grooves 5Y and 6 by means of an improved locking pin I0 which -is fit into registering openingsv II, I2, I3, I 4 respectively opening transversely through ymember I,-element 1, mem ber' 3, and 'element'V 8. The improved 'lockingl pin I0 fis adapted tube-heldin 'place'within'theabove registering openings by' `means-ofv a novel retain- 3 ing element, as will hereinafter be described in detail.

As an illustrative embodiment of the invention, the members I and 2 may be in the form oi two spaced apart, at annular rings rigidly iixed, one relative to the other to form the body of a rotatable friction element for a disk brake or the like, as disclosed in the aforementioned application. The member 3 may be the torque transmitting member of the friction element and has an inwardly projecting lug I5 adapted to be secured for rotation with a rotatable member (not shown) to be braked, and having two spaced apart outwardly projecting lugs IS and I1 .to accommodate opposite ends of two adjacent brake shoe segments (not shown). The two spaced apart elements 1 and 8 may be integrally secured together to form a U-shaped metal strap I8 for holding a securing bar I9 in place to prevent escape of the brake shoe segments during rotation of the assembly. The locking pin Ii! in turn prevents escape of the strap I8.

Referring to Figs. 4 and 5, the improved pin Ii) comprises a body portion 29 having a cylindrical outer surface which fits snugly in the inner surfaces of openings t2, I3 and I4 of element l, member 3, and element 8, respectively, into which said pin may be inserted through opening I! in member i, after all openings are brought into alignment, if necessary, by adjusting position of elements 'I and 3 within the respective grooves 5 and 6. At one end of the pin i9 is formed a flat circular shoulder 2| which is brought into engagement with the inner surface of member 2 to accurately dene the position of said pin when assembled by insertion as above described. At the opposite end of pin I0 is formed a reduced cylindrical portion 22 of lesser diameter than portion 29 and spaced a short distance away therefrom, which portion 22 projects into the opening H in member I in inserted position. The portion 22, being of less diameter than the inner surface of opening II, defines an annular cleairance space 23 to accommodate insertion of a retaining element, as will hereinafter be described. Formed between portions 26 and 22 in pin I9 by machining or the like is a fillet portion 2d, the surface of which merges at its one end with the cylindrical surface of portion 22 at a circular line 25, and expanding therefrom intersects at its opposite end the cylindrical surface of portion 20, forming a circular line of. intersection 26 therewith. With the pin I0 in inserted position, in which position it is shown in the drawing, the plane of theline 2.5 will be dis-v posed substantially flushwith the innersurface of member I, while the plane of the-line-of intersection 26 will be disposed substantially flush with the outer surface of the' element 1 in groove 5, for reasons which will hereinafter become obvious.

According to another feature of the invention and as previously mentioned, a retaining element 21 is provided for holding the pin i9 in place. Referring to Fig. 2, the retaining element 21 may be formed from sheet steel by punching or the like, of substantially the same thickness as the width of the clearance space 9. The element 21 comprises a substantially circular portion 28 of slightly lesser diameter than that of the opening II in member I. Formed integrally with portion 28 and extending radially outward therefrom, in this original form of element 21, is a plurality, in this case four-in number, of cir--A cumferentially spaced apart lugs 2,9t In process of forming the element 21 to its useful form, the lugs 29 will be bent from their attachment with portion 29 to a disposition substantially at right angles to the plane of portion 28, as shown in Fig. 3, to allow for insertion in the opening II in member I and to fit around portion 22 of the pin I 9. The projecting end of each lug 29 is bent outwardly in a shape to agree with the contour of the surface of fillet 24 on pin I 9, so that after the element 21 has been t into opening II, the lugs 29 will extend through the annular clearance space 23 into contact with the surface of said rlllet. By subsequent tapping with a hammer and drift pin or the like held in contact with portion 28, the lugs 29 will be made to feed through the space 23 radially outward into the clearance space 9, during which, the projecting ends of said lugs, originally bent, will be directed by sliding engagement with the surface of llet 24 into space 9 where constraining action of the respective surfaces of member I and element 1 may flatten them. When the inner liat surface of portion 28 of element 21 is brought into engagement with the projecting end of portion 22 of pin I9, the lugs 29 encircling said portion will be bent radially outward into clearance space 9, as shown in Fig. 4, in such a manner as will secure said retaining element 21 in place over the end of pin I0, thereby locking same in place against accidental escape. Any -force tending to urge escape of pin I0 will be opposed by the resistance of lugs 29 to shear, since portion 20 of said pin in tending to move outwardly through opening II will tend to pinch off said lugs at the point where they bend outward into` space 9. Such a force on pin I0 in the present embodiment, during normal rotation of the friction element in which it is assumed to be comprised, would never reach the proportion necessary to shear lugs 29, since said force would result merely from any vibration or shock transmitted thereto in an axial direction with respect to said pin, and no other forces will normally act thereon in this direction.

The pin may be intentionally removed to release elements 1 and 8, for any desired reason, by inserting a drift pin or the like into an opening 30, extending through member 2, intoengagement with the end 2I of pin I0. By--subsequently tapping the drift pin with sufcient force to cause the pin I0 to shear oi lugs 29 of the retaining element 21, said pin may be driven out through the opening II in member I. The diameter of the opening 39 in member 2 is smaller than the diameter of portion 20 of pin i9, so that said pin may not escape therethrough.

After pin I9 has been removed in the above manner, the elements 1 and -maybe pulled from slots 5 and B, allowing the sheared 'lugs 29 to fall free. By reinserting elements 1 and 8 inthe respective slots 5 and 6, aligning their openings I2 and I4 with openings II and i3, reinserting the locking pin I9, and again securing saine in place with a new retaining element 21, in fashion as previously described, said elements 1 and 8 may again be locked in place, secured to members I, 2 and 3.

Summary It will thus be seen that I have provided an improved locking pin and retaining means therefor which are particularly adapted for use in arotatable friction element such as disclosed in the aforementioned application. The locking pin is easily nt in place and secured therein by assembly of an improved securing element which may easily be applied by use oi the simplest of tools, and by use of the same tools also may be disassembled easily. Further, assembly of the pin and retaining element therefor may be effected accurately and conveniently, thus avoiding any possible chance that such assembly will not be reliable.

Having now described my invention, what I claim asnew and desire to secure by Letters Patent, is:

1. In combination, a member having outer and inner surfaces, respectively, and an opening extending therethrough between said surfaces, a pin removably inserted through a portion of said opening and xed in a position in alignmentl therewith, said pin having a taper adjacent one end disposed adjacent to the inner one of said surfaces, a retaining element having a preformed portion contacting said one end and another portion formed during assembly in slidable engagement with said taper and the inner one of said surfaces.

2. In combination, a first member having a first opening extending therethrough, a second member secured to and spaced away from said rst member and having a second opening in registry with said first opening, a third member disposed between said first member and said second member With clearance away from said rst member and having a third opening in alignment with said rst opening and With said second opening, a pin having a sliding it in said second opening and extending through said third opening, said pin having adjacent its one end an annular concave shoulder in registry with said clearance, a retaining element having a preformed portion in engagement with said one end of said pin and another portion formed during assembly in contact with said concave shoulder and extending into said clearance.

v3. In combination, first and second spaced apart members having rst and second openings, respectively, one opening aligned with the other, a pin comprising a part having a sliding t in the first of said openings, and a tapered part adjacent to and centered with the second of said openings, the base of said tapered part being disposed substantially in the plane oi the face of the rst of said members, which face is adjacent to the second of said members, and a retaining element comprising a preformed part disposed in the second of said openings in contact with the end of said pin, said retaining element also comprising a leg attached to said preformed part and formed during assembly in contact with the tapered part of said pin and extending between said members.

GEORGE K. NEWELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,139,337 Brown May 11, 1915 1,175,550 Murray Mar. 14, 1916 1,531,848 Davis Mar. 31, 1925 1,770,893 Fenton July 15, 1930 FOREIGN PATENTS Number Country Date 270.504 Great Britain May 12, 1927 

